DEPT 13C NMR Spectroscopy

Techniques developed in recent years make it possible to obtain large amounts of information from l3C NMR spectra. For example, DEPT-NMR, for distortionless enhancement by polarization transfer, allows us to determine the number of hydrogens attached to each carbon in a molecule. 

Putting together the information from all three spectra makes it possible to tell the number of hydrogens attached to each carbon. The CH carbons are identified in the DEPT-90 spectrum, the CH2 carbons are identified as the negative peaks in the DEPT-135 spectrum, the CH3 carbons are identified by subtracting the CH peaks from the positive peaks in the DEPT-135 spectrum, and quaternary carbons are identified by subtracting all peaks in the DEPT-135 spectrum from the peaks in the broadband-decoupled spectrum. 

C Subtract DEPT-135 from broadband-decoupled spectrum 

Propose a structure for an alcohol, C4H10O, that has the following i3C NMR spectral data  

As noted in Section 6.2, it usually helps with compounds of known formula but unknown structure to calculate the compound s degree of unsaturation. In the present instance, a formula of C4H10O corresponds to a saturated, open-chain molecule. 

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